As an update to my own post:
From talking with CBSA and Transport Canada...
Paperwork required for (most) vehicles older than 15 years is limited to original title/registration and bill of sale from originating country.
Once in Canada, you bring to a CBSA office (at airport, usually in the cargo section) and they physically inspect the bike to match the VIN to the paperwork, and then you fill in a "Form 1" with the CBSA official. Then... You're done!
It is actually easier, paperwork wise, to import an older vehicle from Europe than it is the States.